1. Field of the Invention
The present invention relates generally to the field of miss distance indicators. More specifically, the present invention relates to a digital and analog circuit which when used in conjunction with a miss distance scalar scoring system provides miss distance data to determine the miss distance and miss direction of a missile or the like fired at an airborne target.
2. Description of the Prior Art
Testing of advanced airborne weapons systems, such as missiles and the like, requires a scoring system which may be placed on a target drone to obtain miss distance data including vector, miss distance and miss direction, information.
In the past miss distance scoring devices utilized for airborne scoring of missile intercepts and misses of a target consisted of both cooperative type and non-cooperative type miss distance scoring devices. For example, the BIDOPS 800B, manufactured by the Babcock Company, is a non-cooperative acoustical device which utilizes a doppler shift to measure miss distance of the missile from the target. The AN/DRQ-3, AN/DRQ-3A and the AN/DRQ-4 are miss distance indicator systems which require an RF transmitter in the missile, an RF receiver and transmitter in the airborne target and a ground station to process data. The variety of missiles with which these systems may be used is limited because of the requirement to attach a transmitter to the missile being tested.
Other type miss distance indicators currently in use are either radioactive, static charge, magnetic or photographic in nature. These miss distance indicators are generally laboratory type systems which require special installation and handling precautions.
One particular prior art miss distance indicator is described in U.S. Pat. No. 3,897,151 to James F. Lecroy. Disclosed therein is a laser miss distance indicator which is an electro-optic device utilizing a light emitting diode and an electro-optic scanning system to radiate a hemispherically shaped pattern of electro-optical (light) energy about a target in which the device is installed. When a missile penetrates the radiation envelope, energy is reflected from the surface of the missile. The reflected energy is received by the miss distance indicator through the means of a detector. The detector converts the reflected light energy into an electrical signal which is amplified and processed to extract miss distance and vector information. The information is then transmitted to a ground receiving station where a computer processes the data to produce missile miss distance and flight trajectory information.
Inherent in these prior art miss distance indicator systems is the fact that their useful range is limited to about fifty feet and the fact that these systems are generally not accurate to less than ten feet. In addition, except for laboratory type devices, these prior art devices do not provide vector information which allows for a determination of the direction of the missile. It should also be noted that these prior art systems are often complex in design and very expensive.
A need therefore exist for a miss direction indicator which is relatively simple in design, inexpensive and highly reliable and which will provide vector, miss distance and miss direction information.